ONSTRUCT NETWORK DIAGRAM & CRITICAL PATH

PLEASE SHOW ALL MATH WORK
Construct a network diagram and the critical path
What is the expect completion time?
You can accomplish any one of the following at an additional cost of $1,500
Reduce job 5 by two days
Reduce job 3 by two days
Reduce job 7 by two days
If you save, $1000 for each day that the earliest completion time is reduced which action, if any should be chosen and why?
What is the probability that the project will be completed in 30 days?